1. Field of the Invention
The present invention pertains to audio output jacks. More particularly, the present invention concerns audio output jacks for engaging an audio cable and transmitting a signal to an external audio input device. Even more particularly, the present invention relates to audio output jacks for use with electrical musical instruments.
2. Description of Related Art
In either an electric or an acoustic-electric musical instrument, such as a guitar, bass, mandolin, ukulele, etc., the instrument includes a pickup device for obtaining an electrical signal caused by vibrations of its strings. An audio output jack installed within the body of the instrument transmits the electrical signal to an audio input device, such as an amplifier, pedal, audio recorder, or the like. An audio cable having plugs on opposing ends for interconnecting the audio output jack and the input device. Typically, such plugs on such audio cables include an elongated sleeve and a tip for forming part of an electrical circuit.
Presently known audio output jacks, generally, include a pair of electrical contacts for attaching corresponding lead wires from the pickup device of the instrument to the output jack. Typically, one of the electrical contacts is a negative contact, which functions to ground the electrical connection, and the other electrical contact is a positive contact. The positive contact includes an elongated contact having a bend formed therein to facilitate contact between the tip of the audio output jack and the plug of the audio cable. Once the plug is inserted into the jack of the instrument, the bend engages the tip of the plug and forms a completed electrical circuit.
Usually, when presently known plugs are inserted into the audio output jack of such an instrument, the tip comes into contact with the grounded portion of the jack. This can produce an undesired audio feedback that can damage a connected audio input device.
A number of other disadvantages are exhibited in this structure, such as wasted material on the positive contact, the positive contact becoming deformed and/or deteriorated due to repeated use, debris accumulating around the contacts, and the like which can ultimately lead to having to replace the entire audio output jack.
The prior art has addressed this situation by proposing various alternatives to this typical structure.
For example, U.S. Pat. No. 4,519,287 to Naruse, which issued May 28, 1985, teaches an audio output jack for use in an electric guitar that is disposed outside of the guitar body itself. The jack includes an enclosed structure which prevents debris from becoming lodged between components of the device and maintains a clean electrical connection between the plug and the electrical contacts. Nonetheless, the jack utilizes a pair of electrical contacts or springs having bends formed on the ends thereof for engaging the tip and the sleeve of the plug. As noted above, these bends in the contacts become deformed over time and lose their ability to adequately engage the plug. Furthermore, a great deal of electrically conductive material goes into forming the entire contacts when only the bent ends are utilized, thereby increasing the cost of manufacturing.
Additionally, U.S. Pat. No. 5,522,738 to Lace, which issued Jun. 4, 1996, teaches an electrical connector jack with particular utility in telephones and musical instruments, namely, electric guitars. The jack taught in Lace attempts to reduce the audio feedback exhibited when inserting a plug therein and initially contacting a grounded portion of the jack. Therefore, the jack taught in Lace includes a shorting contact member electrically connected to the sleeve which prevents audio feedback when the plug is first inserted into a guitar. While the jack prevents, unnecessary audio feedback when connecting a plug, the jack still utilizes bent electrical contacts, thereby risking deformation thereof and incurring additional manufacturing costs.
While each of the devices disclosed in the above references are suitable for the uses and problems they intend to solve, there is an ongoing need for improvements in an audio output jack, such as one that reduces the probability of wear on the contacts thereof while simultaneously reducing the cost of manufacturing.
It is to this to which the present invention is directed.